Gamajo Template Loader
, (*1)
A class to copy into your WordPress plugin, to allow loading template parts with fallback through the child theme > parent theme > plugin., (*2)
Description
Easy Digital Downloads, WooCommerce, and Events Calendar plugins, amongst others, allow you to add files to your theme to override the default templates that come with the plugin. As a developer, adding this convenience in to your own plugin can be a little tricky., (*3)
The get_template_part() function in WordPress was never really designed with plugins in mind, since it relies on locate_template() which only checks child and parent themes. So we can add in a final fallback that uses the templates in the plugin, we have to use a custom locate_template() function, and a custom get_template_part() function. The solution here just wraps them up as a class for convenience., (*4)
Installation
This isn't a WordPress plugin on its own, so the usual instructions don't apply. Instead:, (*5)
- Copy
class-gamajo-template-loader.php into your plugin. It can be into a file in the plugin root, or better, an includes directory.
- Create a new file, such as
class-your-plugin-template-loader.php, in the same directory.
- Create a class in that file that extends
Gamajo_Template_Loader. You can see the Meal Planner Template Loader example class below as a starting point if it helps.
- Override the class properties to suit your plugin. You could also override the
get_templates_dir() method if it isn't right for you.
-
You can now instantiate your custom template loader class, and use it to call the get_template_part() method. This could be within a shortcode callback, or something you want theme developers to include in their files., (*6)
// Template loader instantiated elsewhere, such as the main plugin file.
$meal_planner_template_loader = new Meal_Planner_Template_Loader;
* Use it to call the get_template_part() method. This could be within a shortcode callback, or something you want theme developers to include in their files., (*7)
~~~php
$meal_planner_template_loader->get_template_part( 'recipe' );
~~~
* If you want to pass data to the template, call the set_template_data() method with an array before calling get_template_part(). set_template_data() returns the loader object to allow for method chaining., (*8)
~~~php
$data = array( 'foo' => 'bar', 'baz' => 'boom' );
$meal_planner_template_loader
->set_template_data( $data );
->get_template_part( 'recipe' );
~~~, (*9)
The value of bar is now available inside the recipe template as $data->foo., (*10)
If you wish to use a different variable name, add a second parameter to set_template_data():, (*11)
~~~php
$data = array( 'foo' => 'bar', 'baz' => 'boom' );
$meal_planner_template_loader
->set_template_data( $data, 'context' )
->get_template_part( 'recipe', 'ingredients' );
~~~, (*12)
The value of bar is now available inside the recipe template as $context->foo., (*13)
This will try to load up wp-content/themes/my-theme/meal-planner/recipe-ingredients.php, or wp-content/themes/my-theme/meal-planner/recipe.php, then fallback to wp-content/plugins/meal-planner/templates/recipe-ingredients.php or wp-content/plugins/meal-planner/templates/recipe.php., (*14)
Meal Planner Example Class
<?php
/**
* Meal Planner
*
* @package Meal_Planner
* @author Gary Jones
* @link http://example.com/meal-planner
* @copyright 2013 Gary Jones
* @license GPL-2.0+
*/
if ( ! class_exists( 'Gamajo_Template_Loader' ) ) {
require plugin_dir_path( __FILE__ ) . 'class-gamajo-template-loader.php';
}
/**
* Template loader for Meal Planner.
*
* Only need to specify class properties here.
*
* @package Meal_Planner
* @author Gary Jones
*/
class Meal_Planner_Template_Loader extends Gamajo_Template_Loader {
/**
* Prefix for filter names.
*
* @since 1.0.0
*
* @var string
*/
protected $filter_prefix = 'meal_planner';
/**
* Directory name where custom templates for this plugin should be found in the theme.
*
* @since 1.0.0
*
* @var string
*/
protected $theme_template_directory = 'meal-planner';
/**
* Reference to the root directory path of this plugin.
*
* Can either be a defined constant, or a relative reference from where the subclass lives.
*
* In this case, `MEAL_PLANNER_PLUGIN_DIR` would be defined in the root plugin file as:
*
* ~~~
* define( 'MEAL_PLANNER_PLUGIN_DIR', plugin_dir_path( __FILE__ ) );
* ~~~
*
* @since 1.0.0
*
* @var string
*/
protected $plugin_directory = MEAL_PLANNER_PLUGIN_DIR;
/**
* Directory name where templates are found in this plugin.
*
* Can either be a defined constant, or a relative reference from where the subclass lives.
*
* e.g. 'templates' or 'includes/templates', etc.
*
* @since 1.1.0
*
* @var string
*/
protected $plugin_template_directory = 'templates';
}
Usage Example
The Cue plugin from AudioTheme uses this class. Starting at https://github.com/AudioTheme/cue/tree/develop/includes, it has this class in the vendor directory, then the required subclass of my class in the class-cue-template-loader.php file, which sets a few basic properties. It also has a template in https://github.com/AudioTheme/cue/tree/develop/templates., (*15)
If you wanted the playlist to have different markup for your theme, you'd copy templates/playlist.php to wp-content/themes/{your-active-theme}/cue/playlist.php and do whatever changes you wanted. WordPress will look for that file first, before then checking a parent theme location (if your active theme is a child theme), before falling back to the default template that comes with the Cue plugin., (*16)
Change Log
See the change log., (*17)
License
GPL-2.0+., (*18)
Contributions
Contributions are welcome - fork, fix and send pull requests against the develop branch please., (*19)
Credits
Built by Gary Jones
Copyright 2013 Gamajo Tech, (*20)
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